Ahmad Abousamra is believed to be in Syria, and there are reports he could be using computer science skills he learned in Massachusetts to help the violent Muslim organization ISIS.

"They don't have a warrant; they don't have a right to do that," Abousamra is heard saying on a wiretap recorded by the FBI, which lists the Massachusetts man on its most wanted terrorist list.

"Here is a guy that went to terrorist training camps, that expressed his desire to go and fight in Iraq against US troops. That's somebody that needs to face justice," said Vincent Lisi, the special-agent-in-charge of the Boston office of the FBI.

But right now, Abousamra is nowhere to be found. He fled the country in 2006, three years before he was indicted on terrorism charges in federal court in Boston.

Lisi said the FBI has no evidence that Abousamra is involved with the ISIS social media campaign.

"We have no idea," he said. "We don't know where he is or what he is doing."

Abousamra, 33, was born in France and raised in Plainville and Stoughton. He is the oldest of four children.

His father, Abdul Badi Abousamra, was a prominent doctor in Boston and a Muslim activist who founded the Islamic Academy of New England and the Al Noor School. He was also president of the Islamic Center of New England's mosque in Sharon, which his son Ahmad attended for many years.

"This was a very unusual situation where he had everything right in life but took a wrong turn," said Nabeel Khudairi, the spokesperson for the Sharon mosque. "When he was being raised in this society, everything was available to him. He came from a good home, they were affluent, he had a good education, his religion certainly was nurturing to him, but he made a choice that certainly was regrettable."

After attending school in Stoughton, Ahmad Abousamra went to Xaverian Brothers High School for three years. There he was known as "Abou" and was in the science club.

Quiet and reserved to some, his close friends also remember his strident views about oppression of Muslims around the world and his defense of violence carried out by Hamas, the Palestinian terrorist group.

One friend said he even wrote a poem about the Kalashnikov rifle, a weapon of choice for Hamas fighters.

Ahmad Abousamra left Xaverian his senior year, according to friends, in part because the school had banned facial hair and he wanted to grow a beard -- a symbol of religious piety in Islam.

Ahmad Abousamra graduated from Stoughton High in 1999 and went on to study computer science at Northeastern University and then at UMass Boston, where he earned an undergraduate degree.

In November 2001, he got married at the age of 20. He and his wife lived north of Boston and had a child.

The marriage, which took place at North Andover Town Hall, ended in divorce in November 2004. A source close to the family said the marriage broke up primarily because of religious differences. The source said Ahmad Abousamra, a Sunni Muslim, came to view his wife, who was a Shia, as an infidel, not a real Muslim.

In the divorce papers, his wife accused him of "cruel and abusive treatment" on "diverse dates and times." Her lawyer wrote in 2004 that Ahmad Abousamra "fled the country in fear of possible federal and state criminal action against him."

That investigation involved Ahmad Abousamra and his friend from the Sharon Mosque, Tarek Mehanna, who was indicted with Abousamra in 2009 and convicted in 2012.

During Mehanna's trial, friends who were given immunity testified that Ahmad Abousamra wanted to attack a shopping mall and that he believed it was virtuous to fight against American's in Iraq and that the attacks of Sept. 11 attacks were justified.

Team 5 Investigates asked the spokesman at the Sharon mosque if he knew how Ahmad Abousamra became radicalized.

"I don't think it took place from being here at the Islamic Center or any affiliations he had here," said Khudairi. "I believe he was looking for some means to express some inner anger and rage that he had, and he was able to find it by going online and being nurtured by some radical elements from the Internet.'

"We need to figure out where he is, figure out what he is doing and figure out a way to get him back to Boston and in a courtroom," Lisi said.

Ahmad Abousamra's first child is still living in the U.S. Investigators believe he is remarried with at least one other child. Team 5 reached out to Ahmad Abousamra's family in Detroit and Qatar and they did not respond.